Fpmmm Triggers and Rules

You are using an old version of the FromDual Performance Monitor for MariaDB and MySQL (fpmmm). Please consider using a more recent version.

Your InnoDB Redo Log Buffer is too small for large transactions. Make the InnoDB Redo Log Buffer (innodb_log_buffer_size) bigger if you have enough RAM available to avoid additional I/O.
1 Mibyte is good for databases with small transactions. 8 Mibyte is good for medium size transactions. 64 MiByte is good for large transactions.

See also for MariaDB MySQL.

InnoDB plugin is enabled.

The InnoDB Log File (innodb_log_file_size) size is possibly too small.
Choosing a too small InnoDB Log File size can have significant write performance impacts.

For further details please consult MariaDB or MySQL documentation.

MySQL (InnoDB, PBXT, NDB, TokuDB) support Foreign Keys to show relatations between tables. Those relations can be enforced through Foreign Key Constraints.

Foreign Key Constraint Errors are always either a bug in your application (which should be fixed) or inconsistencies in your data (which should be fixed) or both (first fix the bug in the application, then clean-up your data).

Foreign Key Constraint Errors can be found with the following command:

SHOW ENGINE INNODB STATUS<br>G

SHOW ENGINE Syntax …

InnoDB Force Recovery (innodb_force_recovery) is enabled. This mode should be used for data recovery purposes only. It prohibits writing to the data.

Please consult MariaDB and MySQL documentation for further details or InnoDB Recovery Modes.

InnoDB Flush Log at Transaction Commit is set to a values != 1. This can lead to a loss of committed transactions in case of a power failure or an unclean shutdown of your database.

You got an InnoDB Deadlock. Please talk to your development department to fix this problem. Deadlocks are an application problem!

If you are using MariaDB/MySQL 5.5 and newer you should use several InnoDB Buffer Pool Instances for performance reasons.
Some rules to size InnoDB Buffer Pool instances are:

• One InnoDB Buffer Pool Instance should be at least 1 Gibyte in size (innodb_buffer_pool_size / innodb_buffer_pool_instances
  >= 1 Gib).
• InnoDB Buffer Pool Instances you can set equal to the number of cores of your machine.

Binlog format MIXED changes the binary log format (ROW or STATEMENT) depending on the queries (deterministic or not). This makes it impossible to define 100% correctly working binary log filter rules.

If the variable flush_time is set to a non-zero value, all tables are closed (and flushed) every flush_time seconds to disk. This can cause unnecessary and high I/O spikes.

For further information consult MariaDB or MySQL documentation.

The number of table definitions (SHOW CREATE TABLE<br>G) that can be stored in the table definition cache (table_definition_cache). If you have a large number of tables (
> 400) in your database instance, you should consider a larger table definition cache to increase your database throughput and decrease your query latency.
The command SELECT COUNT(*) FROM information_schema.tables; shows you how many tables and thus table definitions you have. The global status Open_table_definitions is the …

The Table Open Cache (table_open_cache or old name table_cache) is a cache to store file handles for all threads. The actual value of cache entries can be seen with the global status of open tables (Open_tables).
Increasing table_open_cache increases the number of file descriptors (open_files_limit) that MySQL requires.
You can check whether you need to increase the Table Open Cache by checking Open_tables and Opened_tables. If the value of Opened_tables is large and you do not use FLUSH TABLES often (which …

The InnoDB Flush Method has changed. This can have an impact on InnoDB write Performance.